Markers of bone turnover for the management of patients with bone metastases from prostate cancer

Although increased bone formation is a prominent feature of patients with o steosclerotic metastases from prostate cancer, there is also some evidence for increased bone resorption. The aim of this study was to compare the cli nical utility of new bone resorption markers to that of bone formation in p atients with bone metastases from prostate cancer before and after bisphosp honate treatment. Thirty-nine patients with prostate cancer and bone metast asis, nine patients with prostate cancer without bone metastases, nine pati ents with benign prostatic hyperplasia and 355 healthy age-matched men were included. Urinary non-isomerized (alpha CTX) and beta isomerized (beta CTX ) type I collagen C-telopeptides (CTX) and a new assay for serum CTX were u sed to assess bone resorption. Bone formation was determined by serum osteo calcin, serum total (T-ALP) and bone (BAP) alkaline phosphatase and serum t ype I collagen C-terminal propeptide (PICP). Fourteen patients with bone me tastases were also evaluated 15 days after a single injection of the bispho sphonate pamidronate (120 mg), Levels of all bone formation and bone resorp tion markers were significantly (P < 0.006-0.0001) higher in patients with prostate cancer and bone metastasis than in patients with benign prostatic hyperplasia, patients with prostate cancer without bone metastases and heal thy controls. In patients with bone metastases the median was increased by 67% for serum osteocalcin, 128% for T-ALP, 138% for BAP, 79% for PICP, 220% for urinary alpha CTX, 149% for urinary beta CTX and 214% for serum CTX. A fter bisphosphonate treatment all three resorption markers significantly de creased by an average of 65% (P = 0.001), 71% (P = 0.0010) and 61% (P = 0.0 015) for urinary alpha CTX, urinary beta CTX and serum CTX, respectively, w hereas no significant change was observed for any bone formation markers. P atients with prostate cancer and bone metastases exhibit a marked increase in bone resorption, which decreases within a few days of treatment with pam idronate. These findings suggest that these new resorption markers may be u seful for the management of these patients. (C) 2000 Cancer Research Campai gn.